Any books wherein the copyright shall be subsisting, first composed or written or printed in the United Kingdom, and printed or reprinted in any other country, shall be and are hereby absolutely prohibited to be imported into the British possessions abroad : Provided always, that no such books shall be prohibited to be imported as aforesaid unless the proprietor of such copyright, or his agent, shall have given notice in writing to the Commissioners of Customs that such copyright subsists, and in such notice shall have stated when the copyright will expire ; and the said Commissioners shall cause to be made and transmitted to the several ports in the British possessions abroad, from time to time to be publicly exposed there, lists of books respecting which such notice shall have been duly given, and all books imported contrary thereto shall be forfeited; but nothing herein contained shall be taken to prevent Her Majesty from exercising the powers vested in her by the tenth and eleventh Victoria, chapter ninety-five, intituled " An Act to amend the law " relating to the protection in the colonies of works entitled to " copyright in the United Kingdom," to suspend in certain cases such prohibition.